Abstract
The aim of this work is to study the kinetics of ultrasound (70 kHz) – using a kinetic model that takes into account cavitation events and drug re-encapsulation upon the cessation of the acoustic field. The simulation allowed the determination of three parameters α, β and λ that define the release and re-encapsulation behavior of this drug delivery system (DDS). The results showed that the drug release increased with increasing power density, as evidenced by the correlation between α and power density. The micelle re-assembly, quantified by the parameter β, also increased with increasing power density. The parameter λ, which is associated with the initial phase of the release process, showed a constant value regardless of the power density. The significance of these results was discussed. Additionally, a comparison between these parameters in folate-targeted and non-targeted micelles showed statistically significant differences for several power densities examined. A better understanding of the kinetics involved in this DDS is very important for the determination of the optimum ultrasound parameters to be used in future in vitro and in vivo experiments.
